Stay With Me
by MaturePopcorn
Summary: AU where Frisk was able to truly save Asriel. As a result, Asriel and Frisk live together like Chara and Asriel did once before. Only this time, brotherly feelings go a little further… Story takes place in the future when Frisk is around 18, Asriel is about the same age.
1. Chapter 1

" **Stay With Me"**

 _By MaturePopcorn_

 **Description: AU where Frisk was able to truly save Asriel. As a result, Asriel and Frisk live together like Chara and Asriel did once before. Only this time, brotherly feelings go a** _ **little**_ **further… Story takes place in the future when Frisk is around 18, Asriel is about the same age.**

 **WARNING: Rated M for HOLY HOT DAMN that's a lot of sex. Sorry if you aren't into that, but… O_o It's happening, so… Don't like, GTFO. 3 If you flame the review section…** _ **You're gonna have a bad time.**_ **Also fair warning, a side ship of Toriel x Sans is gonna happen here, too… ^_^**

 _ **Author's note:**_ …You think this is a joke? Are you having a chuckle? Haha, very funny, I'M the one with a degree. hOi im Kisa, and I looove Undertale more than THE VERY AIR I BREATH. Just kidding (kinda). Undertale has basically got my heart twisted in all sorts of weird knot shapes, and it won't go away (not that I want it to ^_^) so I'm going to write what I've always wanted to happen and hope that one day, one update, it comes true (Yo! Get on that, Toby ^_^) So enjoy what is basically my life now~!

Much love,

~Kisa Alvarez

Chapter 1

Asriel awoke slowly, first opening his eyes halfway, then turning over to his right side just enough to see Frisk, his adopted brother, softly breathing. _"He's so cute when he sleeps…"_ Asriel warmly thought to himself. He yawned, showing his fangs, and stretched, sitting up. Rubbing his eyes, he let his mind drift. _"What day is today… Saturday? I think…? Awesome, a day to relax. What's for breakfast… Hmm…"_ He glanced over at Frisk as the human boy made a small squeaky noise in his sleep and rolled over. Asriel blushed and smiled slightly. _"So calm… And peaceful…"_ He thought for a moment. _"I should mess with him."_

Asriel got up, stretching further, and walked quietly across the room to his human brother. He grinned to himself as he kneeled down to be face level with the sleeping boy. He thought about what he wanted to say, then leaned in close to Frisk's ear. "Frisk… Frisssk…" He whispered.

Frisk moaned softly in his sleep. "N-no… Sleepy… Too early for _that_ … Asriel…" He rolled over and stopped talking. Asriel paused, tilting his head in confusion. _"Too early for… '_ that _'? What is_ that _?"_ Asriel narrowed his eyes and thought of a new thing to say very quickly. "Too early for whaaat, lovey?"

Frisk let out a sigh, which turned into a moan, which woke himself up accidentally. "W-wha…?"

 _"Shit! Ugh… I guess I'll have to wait. I'll get him drunk and ask him,"_ Asriel thought mischievously. He smiled so wide his eyes closed. "Morning, sleepyhead! It's time to wake up!"

Frisk stared back with his almost-classic blank stare, before adding, "It's 7:00. On a Saturday." And before Asriel could respond, Frisk promptly fell right back asleep.

Asriel sighed amusedly. "Fine, fine… I'll eat breakfast without you then…"

Frisk mumbled something that sounded like, "cool don't care", and rolled over onto his side. Asriel ruffled his hair and left, heading down the hall to the living room.

A while later, after Toriel had made pancakes and eaten breakfast with Asriel, Frisk finally woke up for good and came down to eat. "Good morning…" he sleepily mumbled as he shuffled into the kitchen.

Asriel shot him an exasperated but loving look from in the living room. "Howdy…? It, uh… It's past noon, but that's cool. Morning it is."

Frisk giggled, a little more awake now. "Oops… Well, I guess it's your fault for not trying hard enough to wake me up."

Asriel feigned annoyance, retorting, "Do I have to dump water on you every morning…? I will do it." He grinned. "You missed breakfast by several hours, but Mom was gonna meet Sans at Grillby's soon. You wanna come?"

Frisk nodded. "Of course; I love Grillby's burgers." He stopped to yawn and rub his eyes. "L-lemme get ready…" Frisk left the room, and as soon as the bedroom door closed, Asriel got up and followed. He went in as Frisk was getting undressed, earning him an expecting look from the human.

"Sorry, forgot my…" Asriel froze, panicked. _"Shit! I only wanted to see him undress…! I didn't even think of an excuse…!"_

Frisk tilted his head in confusion. "Forgot your…?" he prompted.

Asriel was now sweating heavily. "U-uhhm, I, uh, forgot my… My…" He looked around, desperate to find something, ANYTHING he could just grab and leave. His eyes found something and he spoke without processing. "My pillow!"

…

A silence fell over the room. Frisk resumed his blank stare while Asriel died a little inside. Frisk looked at Asriel's bed awkwardly. "Your… Pillow…"

"I-in case, I, uh, TAKE A NAP at, uhm, Grillby's…?" Even he didn't sound sure anymore. He looked down, avoiding Frisk's gaze, his fur completely red. "I-I'll just, uh, grab it now…"

Those next 15 seconds were the longest of Asriel's life. As he walked out and closed the door behind him, his face still burning, Toriel walked by. "Are you and Frisk ready to go?"

Asriel nodded, still looking down. "Y-yup," he mumbled.

Toriel narrowed her gaze at her child. "Why do you have a pillow? And that expression…" Asriel panicked again, if only momentarily. "Are you two fighting again? You know I don't like it when you fight with your brother…"

Asriel sighed relief, shaking his head. "No, Mom, it was a, uh, joke."

Frisk's voice sounded through the door, adding, "A weirdly unfunny joke."

Toriel opened her mouth to speak, but Asriel beat her to it. "I'M GONNA start walking to Grillby's, I'll meet you guys there okay? Okay bye!" He rushed out the door, still carrying the pillow. A moment later, Frisk came out in new day clothes and smiled at Toriel. Toriel awkwardly smiled back, thinking, _"Why do I have such strange children…?"_ She smiled at this. _"Oh well; life is all the more fun this way."_ She followed Frisk out the door and headed towards Grillby's, Asriel quite a ways ahead now.

Upon arriving at Grillby's, Asriel found Sans already waiting at a booth. He quickly and wordlessly shuffled in and sat down, placing the pillow beside him and burying his face in a menu.

"Heya, kiddo. You seem a little… Off. Anything troubling you?"

Asriel looked up ever so slightly from the menu, blushing at the memory of only a few moments ago. "N-no…! Everything's, uh, fine…" He gave Sans an unconvincing half smile, but before he could respond Toriel and Frisk walked in. They joined Sans and Asriel, Frisk sitting awkwardly next to his brother and Toriel nuzzling up against her boyfriend.

"Hello, Sans~!" Toriel blushed lightly and scooted closer to Sans.

"Hi Tori, Frisk. How're you doing today? It's a beautiful day out. I was thinking that after this, we could take a walk around Snowdin. Maybe watch a movie at my place."

Toriel smiled. "Sure! Anything with you would be fun…"

Frisk rolled his eyes and Asriel feigned a moan of exasperation. Toriel always got like this around Sans. It came with having a brand new boyfriend around…

Frisk turned to looked at Asriel, staring for an uncomfortably long time. Asriel pretended not to notice at first, but started blushing after only five seconds and kicked his brother under the table. Frisk winced only momentarily, and resumed staring. The table was now silent, Sans and Toriel watching in confused amazement as Frisk stared down Asriel, who in turn pretended to study the menu with all his concentration. Finally, he couldn't take it anymore. He turned to Frisk, wide-eyed, about to ask what he was doing when Grillby came over.

"Hiya, Grillby. I'll have my usual." Asriel breathed a sigh of relief as Sans broke the horrible silence at last.

They all ordered and ate in relative peace for the rest of the meal, only breaking it to talk about going-ons in the Underground and surface; Papyrus's latest antics, Toriel's pay-raise at the school, and so on. When they finished, they walked all the way to the entrance to the Ruins and back, stopping at San's house for a movie.

Frisk yawned. At only 3:30 in the afternoon, he was already looking forward to bed. "I think I'll go home. You guys watch your movie without me."

Toriel sighed. "Alright, my child… But behave yourself. And Asriel… Why don't you go to? You can catch up on your reading… Or…" She trailed off, not sure how to finish her sentence.

Sans grinned. _"I sense an ulterior motive…? Okay, Tori, alone time it is."_

Asriel got the hint and nodded, heading for the door. Toriel went back to the kitchen to make popcorn, and Sans stopped Asriel at the door. "Hey bucko, you never answered me back there. What's up? Something troubling you?"

Asriel grinned nervously. "N-naah, just kinda… Tired. I don't feel very good either, I think I might be sick."

Sans looked thoroughly unconvinced. "Okay, well… At the very least, take this," he said, handing him an unmarked package from seemingly nowhere. "Open it when you get home, okay? You might need it."

Asriel blinked and said thanks, a little confused. The door had just closed and he was barely to the library when he started opening the box. Inside was a note:

 _I know what's really going on here, kiddo. Be safe._

 _-Sans_

Under the note were three condoms and a bottle of lube. Asriel dropped the box, with its contents and covered his mouth, blushing. _"Sans knows… Sans_ KNOWS! _How could he possibly know…?! Have I been that obvious…?"_ He paused. _"Maybe… Maybe he's right. I should just go for it… Sans wouldn't have given me this stuff if he didn't think I at least had a chance."_ He took a deep breath and picked up the box. He exhaled, opening his eyes. "I've just gotta stay determined…!"he said to himself, and hurried off towards the Ruins.

The house was silent when Asriel opened the front door. He placed the box on the dining table and went to the fridge, pouring himself a glass of milk. He sighed, leaning against the wall. _"What should I say to him… Should I say anything at all…? M-maybe this can wait…"_ He shook his head. _"No, this can't go on any longer! I have to tell him how I feel. Even if… What I_ really _want doesn't happen. He at least needs to know."_ He didn't dare let himself think of what would happen if Frisk liked him back. The thought, while so blissful in his mind, seemed so unlikely in real life. _"I… Don't get ahead of yourself, Asriel. Whatever happens, happens."_ He breathed out and walked into the living room.

Frisk was in the living room.

The box was in Frisk's hands.

Frisk was blushing.

Everything slowly went white as the floor rushed up to meet Asriel.

Asriel slowly woke up to Frisks face barely three feet away. He sat up too quickly, and immediately regretted it. The pain was unbearable, and Frisk gently pushed him back down onto the bed. "Don't move. You hit your head pretty hard, and you could really hurt yourself if you don't relax."

Asriel moaned. "Wha… What did I even do…?"

"You fell. You've been out for ten minutes."

Asriel blushed. "R-right, before that…" Suddenly everything came rushing to the front of his mind and he almost fainted again. "Aah… Aagh! Y-you…! Box!" His entire face turned red as he spotted the box still on the table. He flipped over, burying his face into the rug.

Frisk blushed. "Y-yeah… The box… Um, did Sans give you that?"

Asriel moaned what sounded like "Mm-hmm" and Frisk sighed. "Well… Do you? Do you like me that way…?"

Asriel whimpered softly. _"Yes! I've always liked you! I… I want to be with you for the rest of our lives…!"_ All he could do was think the words he so desperately wanted to say. They stuck on his tongue, unable to come out. _"F-Frisk…!"_ Then came the tears. His soft crying was just barely audible through the wool rug, and Frisk smiled softly, rubbing Asriel's back through his shirt.

"Asriel…"

Asriel sniffed and stopped crying, though barely. He turned back over and looked at the boy he loved, unable to stop blushing and whimpering at the same time. Frisk closed his eyes and leaned down, kissing Asriel on the tip of his snout. "I love you too," he whispered.

Asriel stopped whimpering, compensating with extra blushing. "F-Frisk…?"

Frisk just giggled, smiling happily. "I know I should have told you sooner… It was so obvious how you felt about me, but… I was still scared. Irrationally scared. So I confided in Sans, and… Well, I think that's why he gave that to you. He knew I would say yes."

Asriel absorbed all this, and took a deep, shaky breath. "S-so… We can be together…?"

Frisk laughed at this. "Of course, silly. Otherwise I wouldn't have kissed you."

Asriel blushed. "So…" He hesitated, unsure of what to say now. Thankfully, Frisk said it for him. "The box?" Asriel nodded.

Frisk blushed rather deeply. "Y-yeah… Um… Do you wanna, maybe… Go to our room?"

Asriel's heart skipped several beats and his stomach turned over in excitement, happiness, and love. He tried to say yes, but all that came out was an excited squeak. Frisk nodded and helped Asriel up, supporting him back to their room. The second the door was closed and locked, Frisk had already gotten his shirt off.

"F-Frisk!" Asriel stared at the human boy's body. His skin was smooth, hairless, and tan, and he was just slightly toned. Asriel could feel himself getting hard through his jeans as he fumbled to get his own shirt buttons undone. Frisk grabbed Asriel's hands, stopping him, and kissed him on his mouth. They were both a little startled at the sensation, but enjoyed it nonetheless. They released each other's hands, and Asriel's hands began wandering over Frisk's bare chest while Frisk unbuttoned the rest of Asriel's shirt. They broke the kiss only to slide Asriel's shirt completely off, and Frisk hastily unbuttoned his own pants. They resumed the kiss, only this time their hands began wandering to other places…

Asriel moaned softly as Frisk's hand slipped under his boxers and touched his manhood. They broke the kiss again as Frisk started jacking Asriel off, and after a few moments of nuzzling like this, Frisk brought his head down to Asriel's jeans. He took hand out only to unbutton and unzip them, pulling them down around Asriel's knees. He pulled his boxers back just enough for Asriel's eight inch cock to come out, along with his balls. Frisk inhaled sharply and felt his stomach flip in love and lust. He brought his head down to Asriel's tip and hesitated only a second before putting his tongue to it. Asriel immediately squirmed in the bed and moaned loudly, only encouraging Frisk to put more in his mouth. Before long, almost six inches were in Frisk; the tip hit the back of his throat, and he couldn't fit any more. Using his tongue to play with the most sensitive parts, he stared thrusting from his neck, up and down… Up and down… Asriel was panting heavily; it was all he could do to not cum immediately. He grabbed Frisk's jeans at his hips and pulled them down without bothering to unzip them. Frisk stopped sucking to pull his boxers down, revealing his almost six inch cock, before resuming his previous action. Jacking himself off while sucking Asriel, Frisk started moaning softly in pleasure.

"F-Frisk…"

Frisk made a sound that indicated 'no', and Asriel whimpered. "F-Frisk…! I… I'm…"

Frisk realised what Asriel was so concerned about and started sucking faster, going down so fast that he was starting to hurt the back of his throat. But he didn't care. The moans given off by Asriel, the body heat from his crotch… Everything made it worth it. He kept going, and eventually he heard the loudest moan yet, followed by a sharp intake of breath. He braced himself, and flinched slightly at the salty taste of cum as it hit the back of his tongue and dripped down his throat. Asriel kept cumming… And cumming… There was so much that it started overflowing out of Frisk's mouth, dripping onto Asriel's balls and Frisk's chest. Frisk then came as well, this time landing all over the bed and splattering onto Asriel's legs and boxers, which were still around his knees. Frisk came up far enough for Asriel's cock to come out of his mouth and collapsed, his head on the monster's chest. He panted heavily as he pressed his naked body as close to Asriel's as he could. They cuddled like this for several minutes before Asriel broke the long silence.

"That was… Fun."

Frisk snorted. "F-fun?" He laughed, adding, "Wait until we actually use the stuff in the box. And, uh… some other stuff…"

Asriel blushed. "'O-other stuff'?"

Frisk nodded. "You don't really think _you're_ top, do you? I only went down on you tonight because I was horny. Just wait until next time…~" He grinned mischievously at this, and kissed Asriel's chest. Asriel closed his eyes and smiled. He was perfectly fine with being bottom. Especially because it meant Frisk got to have more fun, which made him happy.

He kissed the top of Frisk's head. "I love you…"

Frisk nuzzled his head deeper into Asriel's chest. "I love you too… Goodnight, lovey," he said with a deep yawn.

There was a silence. It stretched on for several minutes…

Asriel's eyes burst open. "Is _that_ what the collar under your bed is for?!"

 **Author's note: Whelp. I did it. Undertale, minimum of 3,000 words. O_o IT IS DONE**

…

…

… **Except… Not really… Becaaause…! There shall be more chapters! In which collars are explored! And, y'know, anal and stuff… *trails off* and stuff… stuff *mumbles* ANYWAY yeah, I'm tired… Also, to Alex of coc: I APOLOGIZE! Lol I know it's a few days late, but here it is! The story I told you about! ^_^ Can't wait for you to read it :b**


	2. Chapter 2

" **Stay With Me"**

 _By MaturePopcorn_

 **Description: AU where Frisk was able to truly save Asriel. As a result, Asriel and Frisk live together like Chara and Asriel did once before. Only this time, brotherly feelings go a** _ **little**_ **further… Story takes place in the future when Frisk is around 18, Asriel is about the same age.**

 **WARNING: If you read the first chapter, you don't need a warning. But, because I don't like getting flagged… THERE IS SOOO MUCH SEX IN THIS STORY (There's your warning).**

 _ **Author's note:**_ I like where this story is going. I like it enough to… WRITE A SECOND CHAPTER! And this time… EVEN MORE SEXUALS! So enjoy this thing I did at two in the morning. ^_^

Much love,

~Kisa Alvarez

Chapter 2

"Nnmmm…?"

Asriel slowly blinked his eyes open and looked down at Frisk, fast asleep with his head buried into Asriel's chest. The human boy made cute noises when he slept, which calmed Asriel as he sighed, listening to the steady breathing of his lover on top of him. He reached over to the nightstand beside their bed and looked at his phone. It was 9:27am and Toriel had texted him about an hour ago, saying only, "I'm still at Sans' house, but I promise I'll be back home in time to make dinner. I love you my child ^_^".

Asriel's mind raced excitedly. Knowing Toriel, this meant she wouldn't be home until at least 5:00. That left all the time in the world for him to fool around with his new boyfriend. He smiled and looked down at the still sleeping human. He started gently pushing him awake. "Frisk… Wake up, I'll make us breakfast…" he whispered into his ear before kissing the top of his head.

Frisk mumbled in his sleep softly. Asriel giggled and whispered a little louder, "What was that?" hoping to prompt the boy to repeat himself.

"…Nmm… Boop your snootle…"

Asriel tried in vain to keep his laugh quiet, and Frisk slowly woke up, blinking against the light and moaning tiredly. "Mmm…! Why are you awake…? Go… Go back to sleep…" he said yawning, rubbing his eyes.

Asriel shook his head, long ears swooshing past Frisks head. "Nope. I'm hungry. Come on, I'll make us breakfast!" He got up, effectively throwing Frisk off the bed. After a moment of complaining from the ground, Frisk got up and followed Asriel down the hall and into the kitchen, muttering, "Fucking asshole…" under his breath.

Asriel giggled at Frisk as they got to the kitchen. "You really aren't much of a morning person, are you?" Frisk shook his head solemnly. "That's fine; I have something that will wake you up in an instant." Asriel got out pancake batter and milk from the fridge, pouring them each a cup and pouring some batter into a pan. He didn't bring the milk to the table, however, which puzzled Frisk. When the four pancakes were done, he brought them to the table on a large plate and went back into the kitchen.

"A-Asriel, what… Why do you have that?" Frisk asked, startled, as Asriel walked back into the living room with two cups of milk, two shot glasses, and a bottle of vodka.

Asriel smirked. "You're tired, aren't you? I told you I had something that would wake you up."

Frisk hesitated, then took the shot glass and cup of milk from the monster boy. "It doesn't mean morning drinking is good, but… Anyway, won't mom find out?"

Asriel poured two shots out. "Nah, I'll replace it with water. I haven't done it to this bottle yet, so it'll be really strong. She never notices when I do this, trust me," he responded smiling, handing Frisk a full shot of vodka.

Frisk smelled the strong scent of alcohol and immediately felt his body get weak, anticipating the feeling about to come. He took a rather shaky breath. "O-okay… I hate doing this so early in the morning though, but…" He shook his head and downed the shot, then scrambled to wash it down with milk.

Asriel giggled again. "You're funny." He quickly downed his own shot and, without washing it down, poured another and drank that one just as quickly.

They started eating, and by the end of their meal, they had both had four shots each. Asriel was trying to balance a spoon on his snout, and Frisk was busy humming a song and dancing in his chair, eyes closed. Finally, at about half past nine, the two boys got up and cleared their dishes. Asriel replaced the missing alcohol with water, and cleaned the shot glasses. The stumbled back to their room, giggling, and Frisk immediately flopped onto their bed. He hiccupped and blushed, looking at his boyfriend. "Hey Azzy… Hey, haha, wanna go take a shower…? It's more fun if we're together…"

Asriel giggled, blushing as well. "Mmm, haha…! Yeah, let's take a, uh, shower…!"

They stripped naked, showing no concern for privacy, and quickly ran to the bathroom. Once inside, Asriel turned the water on and got in. Frisk followed, and before either boy could say anything he fell onto the floor.

Asriel laughed, "D-do you want help then?"

Frisk blushed and shook his head vigorously. "N-NO! I meant to do that… See, I, uh, I'll prove it!" He got to his knees and added, "This was intentional, see?" and promptly grabbed Asriel's ass and put his mouth on the monster boy's tip. Asriel gasped in surprise, which quickly turned into a moan of pleasure.

"Nmm… Yeah… You, uh… Definitely meant to do that… Haah…!" Frisk kept sucking like this for a few minutes before taking the now rock hard cock out of his mouth and standing back up. He smiled and wiped the trail of precum from his mouth away, blushing heavily. "T-there, I did what I wanted to. Now we can, uh, get clean or whatever…"

Asriel giggled and started absent mindedly jacking off. "Get clean… 'Or whatever'… You're cute when you're drunk…"

Frisk blushed even harder and giggled, grabbing the shampoo bottle and washing his hair slowly and thoughtfully. When the two boys finally finished, they had sobered up slightly. Asriel kissed Frisk on his cheek as they got out and started drying off, and Frisk snuggled up to Asriel's naked body. "Mmmm… You're so warm…" He said lovingly as he hugged his boyfriend.

Frisk squealed as Asriel picked him up and carried him bridal style back to their room, still naked. He laid Frisk down onto the bed and sat on the edge of the bed, turning on their TV. Frisk blushed as he looked at Asriel's ass, his tail barely a foot from Frisk's head.

Asriel lay down next to Frisk as Netflix loaded up, and Frisk instinctually cuddled up to his boyfriend. "Let's just cuddle here all day…"

Asriel giggled. "Sure…! I can't see why not… And, if we're gonna be here all day, I don't really see the need to put on clothes, so…"

Frisk blushed and giggled back. "Silly Azzy, why would we put on clothes…?"

Asriel kissed his boyfriend on his forehead and sighed happily, holding him closer. Frisk laid the side of his head on Asriel's chest and nuzzled in closer.

They lay there for hours, watching movie after movie, and eventually fell asleep together. Nothing sexual came out of their naked Netflix binge, just cuddling and kissing and sleeping together. When they woke up at around 5:00, they had completely sobered up and were quite hungry.

"Children, I'm home!" Toriel walked into the house and smiled, remembering _her_ day with Sans. Eating lunch at the M.I.T. resort restaurant, going to the movie theaters… It was one of the nicest dates she had ever had, and the way it started… She blushed madly as she remembered this morning. _"The way he kissed me good morning…!"_ She sighed happily and called again, "Children, I'm making spaghetti for dinner tonight! Sans and Papyrus are coming over!"

Asriel nuzzled Frisk's head, softly whispering, "We should probably get dressed…"

Frisk smiled, his eyes still closed. "Yeah, I suppose… But I don't wanna get up…"

"Sans and Papyrus are gonna be here soon, though…"

Frisk sighed. "Nmm… Okay… I, uh… Haah… I really don't wanna get up…"

Asriel giggled and kissed his boyfriend on the cheek. "It's okay, just lay there. I'll get your clothes for you…"

Asriel slowly got up, Frisk falling off his chest and onto the bed. The monster boy walked to their shared wardrobe and picked out outfits for both of them, bringing them back to the bed. Frisk looked up at Asriel as he put on a shirt and sat up on the bed. He continued staring at his boyfriend until Asriel started blushing. "W-what?"

Frisk smiled sweetly. "Can you come here?"

Asriel leaned in closer to Frisk, and the human boy moved his hand faster than Asriel thought possible. "Boop!" he exclaimed as he poked the monster boy on his snout. "Ahaha! I booped your snoot!"

Asriel blushed. "F-Frisk…?! Wha- Auugh!"

Frisk fell back down laughing, tears running from his eyes. "I can't believe you always fall for that!"

Asriel smirked and grabbed Frisk's wrists. Smiling, he looked straight into his eyes and said, "I will tickle you. Until you scream. And then I'll keep going."

Frisk widened his eyes. "W-woah there, Azzy, let's take a step back here. We can talk about this!"

Asriel let out a loud, "Ahahahahaha!" as he grabbed Frisk by his stomach, tickling him mercilessly until Frisk was crying loudly. "HAH, O-OKAY AHAHA, STOP PLEASE AHHH!"

Asriel stopped and Frisk took a deep breath. "Air…! I… I need air…!" Asriel laughed as Frisk took deep breaths and growled faintly. "I… I fucking hate you…"

Asriel giggled. "Yeah, right. Not after the shower we took you don't."

Frisk blushed. "Well, that'll be the last time unless you're nicer to me," he said, crossing his arms and turning to face the wall. Asriel shrugged and put on his underwear, followed by his pants. He draped all of Frisk's clothes over the naked boy's head, who (to his credit) didn't break from his 'upset' pose. Frisk sighed very shortly and grabbed his shirt from the top of his head and, putting the rest of his clothes onto the bed beside him, started getting dressed.

As the two boys went down the hall and into the living room, Sans and Papyrus walked in through the front door. Asriel grinned, knowing that dinner was about to get a lot more fun.

"Human! Prince! How great it is that you are able to dine with I, The Great Papyrus! And how great that the one cooking our meal is none other than I!"

Sans grinned. "Sorry, Paps. The queen already made dinner."

Papyrus sighed. "Oh… Alright then… Well, what are we having?"

"Spaghetti."

"NOOO! The queen made spaghetti without my help?!"

"Sorry, Paps. I thought I told you. Must have slipped my mind."

Frisk giggled and Asriel instinctively blushed at the sound of his laugh. He made brief eye contact with Sans, and an understanding passed between them, unbeknownst to the other people in the room.

"Hey, Human! Has Undyne taught you how to cook yet? We should all do a joint cooking lesson together! We can make my specialty: Spaghetti!"

Asriel rolled his eyes, smiling. _"Spaghetti, spaghetti… So much pasta in this household…"_

Toriel came out of the kitchen, smiling and holding a large bowl of pasta. "Hello, Papyrus! Sans! I hope you're hungry, because I made a lot of spaghetti…!"

Papyrus smiled widely. "Wowie! I sure hope it's as good as mine…!" He paused for a second. "Nonsense! No spaghetti could ever be better than _my_ spaghetti!"

Toriel giggled and sat down, not taking any insult at this. Sans sat himself next to her, Papyrus took one of the end chairs, and Asriel sat across from Sans, with Frisk sitting next to him. The bowl was passed around to everyone's plates, and everyone except Papyrus grabbed bread, who was saving room for more spaghetti. The dinner was warm and fun, and everyone laughed and told stories. Around 6:00, there was a knock on the door.

"Oh, I wonder who that is…?" Papyrus said, _very_ unconvincingly, and he got up and dashed to the door. Opening it, they saw Undyne in her leather jacket holding a bottle of red wine with Alphys behind her, wearing a nice clean dress.

"Hey Sans! And Toriel, Asriel, Human…! Papyrus invited me over, but I figured he didn't ask you first, so I brought this as a gift!" She said proudly, holding up the bottle. "Also, Alphys wanted to see you guys, so she tagged along."

Alphys blushed and smiled meekly. "H-hi everyone! I hope us dropping by isn't too much of an inconvenience…!"

Toriel rolled with the situation smoothly, laughing, "The more the merrier! We have plenty of food, come in!"

An extra chair was pulled up, and Undyne and Alphys shared the end opposite Papyrus. Everyone was having a wonderful time, now with alcohol, and Toriel was just telling a story about the students at her school when there was a knock on the door, causing Alphys to jump in her seat.

Undyne looked at Alphys skeptically. "Alphys, do you know about this…?"

Alphys blushed and buried her head in her hands. "I, uh, tried to say no, but when he found out we were coming over here…"

"HELLO, Darlings!"

Frisk winced as the door slammed shut, no doubt by Mettaton himself, and Papyrus practically sprinted to the main entrance. "Mettaton! You came!"

"Pappy, darling, when I heard you were here, I couldn't help but make an appearance! And not being invited, I brought my finest wine as a gift to help forgive my rudeness."

Toriel smiled, now a little concerned about the number of people in her house. "Not at all, Mettaton! You're always welcome here. Just, ah, try not to break anything this time."

Mettaton strolled into the living room, and pulled up another chair next to his skeletal boyfriend. By 7:00 that evening, it seemed everyone was a various level of tipsy, including Frisk and Asriel. The whole house was full of fun times and laughter, and it seemed the night would last forever. They all stayed up quite late playing party games, cuddling with their various partners, and generally having a good time. At around 11:00, another knock was heard at the door. When Toriel opened it, she stifled a gasp before recognizing the spider before her as Muffet.

"Hello, darling. I can't stay long, I have much late night business to attend to. Mettaton informed me of your party, and I thought I might drop by to give you some of my pastries! Free of charge." She paused, smiling. "You know, ever since your child fell down here, our lives have gotten much better, I must say. The spiders trapped in the ruins have made it back to their home with me, and we finally live together happily. I think I might like to hire him as an assistant in my new bakery…" She grinned. "I'd take good care of him, I promise… Ehehehe…! Well, darling, I must be going. I'll see you around…!" And with that she turned and left, leaving a very confused Toriel with a basket of baked goods.

She closed the door and strolled back in. _"Well, tonight's been fun."_ She thought happily, giggling.

Finally, around 1:30 am, everyone started shuffling out of Toriel's house. First Undyne and Alphys, then Mettaton and Papyrus, who had to get permission from Sans to spend the night at Mettaton's apartment. There was a brief and serious exchange between the Sans and Mettaton before they left, and Asriel noticed it was a very similar experience to the one he had with the skeleton the day before… He shuddered. _"Paps and Mettaton are cute as a couple, but…"_ he shook his head. _"Yeah, try not to think about how that would even work."_

Toriel said goodnight to her children, asking, "Sans, are you going to spend the night here?"

Sans nodded, "Sure Tori, I'll be right there." Toriel walked back to her room, leaving Sans alone with Asriel and Frisk. He sighed and addressed Asriel first. "Alright, kiddo, I can see that everything worked out in your favour. That's awesome. But you better be using that box… You need to stay safe, alright?"

Asriel and Frisk blushed. "Y-yeah, Sans, but… This is a really weird conversation to have with you…"

Sans chuckled. "Well, you'd rather Tori had it with you then?"

Asriel shook his head so hard his ears smacked Frisk in the face. "Ow…?"

"S-sorry…! No, Sans, not that…"

Sans nodded in understanding and agreement. "Alright then. Then you'll be safe. 'Cuz if you don't…" he blinked. "You're gonna have a bad time."

Asriel smiled nervously. "Ahaha…! Y-yeah, Sans! We'll be safe, promise!" And before the skeleton could say any more, he grabbed Frisk's hand and bolted off to their room.

It wasn't until 2:00 am when Frisk and Asriel were finally ready for bed. Frisk put his head on the pillow and almost instantly fell asleep. Asriel giggled and got into bed next to his boyfriend. He smiled as he snuggled up to Frisk, spooning. Whispering in his ear, "I love you…" as he fell asleep, Asriel smiled as he thought of what would happen tomorrow night with his lover…

Pre-Authors Note: This was going to be a little longer and involve actual sex with the collar, but the plot worked better this way. Sorry! Sex is next chapter now lol ^_^

Authors Note: I'm currently writing this at a coin club meeting… Where my dad collects old coins… And there are a lot of old white conservative men. And here I sit, writing gay fanfiction. Beautiful. Also a boy my age looked over my shoulder to see what I was writing (Rude as fuck, BTW) while they were having sex in the shower. He, uh… He's looking at me weird now… Ahaha what have I dooone…! Oh well. :D The story is done! Chapter 2 anyway. Ready for Chapter 3…?! Because I'm not. Where's the story going? AHAHA WHY WOULD I KNOW I'M ONLY THE AUTHOR I MEAN I KNOW THEY'RE GONNA HAVE SEX BUT THAT'S ABOUT IT (I may have to consult my friend from COC for this…) Well, I've rambled enough. Did you enjoy the story? I hope so. It took a while to get past my writers block. So please, review if you enjoyed it! Motivation me so I can write chapter 3! Lol DETEMMINATION and good night. ^_^

P.S. Microsoft Word keeps trying to tell me that "the human boy" should be changed to "the human body" and when referring to Frisk, it kept trying to change "who" to "which". STOP OBJECTIFYING FRISK, YA DICK!

P.P.S. I'm very tired…


	3. Chapter 3

" **Stay With Me"**

 **By MaturePopcorn**

 **Description:** AU where Frisk was able to truly save Asrie. As a result, Asriel and Frisk live together like Chara and Asriel did once before. Only this time, brotherly feelings go a _little_ further… Story takes place in the future when Frisk is around 18, Asriel is about the same age.

 **WARNING:** This chapter contains MUCH SEXUALS. Like, really. This is the chapter where they finally DO IT. ^_^ So have fun with that… (Rated M+)

 **Author's note:** WOW I am so sorry this is a little late…! Aughh! I've been sick lately, and with school… But here it is! In all it's smutty glory! Lol I hope you enjoy it…! ^_^

Much love,

~Kisa Alvarez

Chapter 3

Asriel woke up with a rather unattractive snort, suddenly wide awake. He glanced over at the window in his room and, seeing that it was still dark, sighed and closed his eyes. Unable to sleep, he nuzzled his head into his boyfriend/adopted brother's neck sleepily, smiling to himself as the human boy made little noises in his sleep. The monster boy then looked at the clock beside their bed. 5:08 am. Asriel groaned, and his stomach growled. He still had quite a while before everyone else woke up, and he was hungry; his body believed it was breakfast time. Luckily, he knew where Frisk kept a hidden supply of chocolate in their room... But getting it would not be easy.

He sat up ever so slightly, barely moving the human boy beside him. He thought about how to complete his mission _very_ carefully. He had two options: he could either carefully attempt to sneak his way to the closet, where the door was quite creaky, and sneak his way back into bed without waking Frisk... Or he could bolt out and grab it, run to the bathroom and jam it down his throat, not caring if he woke his boyfriend. He breathed in heavily and looked longingly at the closet before choosing the latter, silently jumping out of bed and dashing to the closet. By the time he grabbed two dark chocolate bars, Frisk was already sitting up and blinking, trying to figure out what was happening.

Asriel squeaked as he stubbed his toe on the bedframe on the way out of the room, and Frisk caught a glimpse of what was in the monster boy's hands. "Hey! Those are my last two chocolate bars!" But Asriel was already in the bathroom, where he locked the door and ripped the wrapper off the first bar, shoving it in his face. Frisk was now up and in the hallway, leaning against the bathroom door and moaning.

"Aaazzy...! Those are miiine...!" He sleepily yelled through the door. "Give 'em baaack..."

There was a pause, and Asriel slowly opened the door; Frisk soon saw that he was too late. Both chocolate bars were nowhere to be seen, and Asriel's soft white fur was stained a suspicious dark brown around his snout.

Frisk growled lowly. "I can't say I entirely blame you... I know how you get around chocolate... And strawberries..."

Asriel's semi-scared expression turned into a half smile. "So we're cool then?"

Frisk snorted. "Of course not. You owe me _big_ time for this..." He spoke softly and seductively.

Asriel shuddered as cold hands touched the back of his neck; Frisk was wrapping himself around his monster brother, thief bodies intertwining.

"Now let's see..." He whispered, licking some of the chocolate off Asriel's snout. "How can you pay me back for this...? You know I was looking forward to that chocolate..."

Asriel started shivering. "F-Frisk, I'm cold... Can we go back to bed?"

Frisk shook his head. "Nope. You still have to make it up to me..." He closed his eyes and kissed Asriel on the forehead. "By making me pancakes."

Asriel paused, then laughed. "Okay! Come on, I'll make 'em now."

Frisk raised his eyebrows. "At five in the morning?"

Asriel nodded vigorously, his ears flopping up and down wildly. "Yup."

Frisk sighed softly. "Ok... I'm hungry now anyway. I'm surprised we didn't wake up mom though..."

Asriel then realised that Frisk was right; surely Toriel would've heard all that noise they had made…

"Maybe she's just hungover...?"

Frisk shrugged, muttering a quiet "Maybe" before yawning widely.

Asriel giggled and grabbed his brother's hand, walking into the kitchen. Upon arriving at the stove, Asriel found a note plastered to the microwave.

 _Asriel and Frisk,_

 _Me and Sans couldn't sleep last night, so we slipped away to Snowdin to hangout at Grillbyz. Please forgive me for this... Breakfast is in the fridge!_

 _Xoxo Mom_

Frisk chuckled. "She's getting really lax with the whole parenting thing, isn't she...?" He read the note again. "Breakfast is in the fridge...? So she made breakfast at who-knows-when in the morning and then left? Wow."

Asriel stretched. "It's cool, though. She left the newer vodka in the freezer, so if you wanna...?"

Frisk shrugged and opened the fridge, pulling out pancakes on a plate and putting them in the microwave. He then opened the freezer and pulled out the nearly full bottle of Grey Goose. "I guess a little wouldn't hurt. And besides, you're gonna need it for later."

Asriel blinked as the timer went off for the microwave. He opened the door and pulled them out. "Later? What... What's later...?"

Frisk opened the bottle and smiled. "For when you pay me back for eating my chocolate." He drank straight from the bottle, downing about 3 shots worth before handing the bottle to Asriel, smiling widely.

Asriel just stared, amazed. Then he shook himself back and stuttered, "P-pay you back? But..."

Frisk shook his head dreamily. "Mom made breakfast, yeah? That means you still haven't paid me back."

Asriel gulped and looked at the bottle for a second, then put it to his lips and swallowed a full 4 shots worth.

Asriel recoiled at the taste but forced it down. "Okay, no more. No more alcohol for now." He capped the bottle without replacing the missing vodka with water, placing it back in the freezer.

They ate their pancakes somewhat quietly until the alcohol hit them like a bus. Then they were substantially louder, singing and laughing as they drowned their pancakes in syrup and strawberries. When they finished, they cleared their plates and stumbled back to the bathroom, climbing into the shower together. The stripped while in the tub, throwing their clothes onto the tile nearby, and turned the water on hot.

Frisk buried his face into Asriel's soft white fur, sighing happily. "It's... So warm..."

Asriel only giggled in response, starting to shampoo his fur. Frisk's hands were already wandering, however, and they soon found themselves at Asriel's waist. Asriel started panting and moaning a little, Frisk's hand reaching around to the monster's boy semi-hard cock. As he started to jack him off, Frisk whispered softly, "You're not getting off easy for what you did..." into the monster boy's ear. Asriel moaned louder, nuzzling his head backwards into Frisk's.

"K-keep going...!" He was now panting heavily and the shampoo had fallen to the floor. As the bubbles rinsed out of Asriel's fur, Frisk, who had already washed his hair by this point, stopped pleasuring Asriel and smirked.

"Let's go back to bed... I'm sleepy..."

Asriel squeaked slightly; there was something about the way Frisk said "bed..."

They didn't even bother drying off, instead turning the shower off and stumbling back to their room, naked. Asriel got on top of the covers, waiting for his boyfriend, but Frisk dropped to the floor and began looking under the bed instead. He pulled out a plain looking box…

Asriel gasped quite loudly. He blushed and readjusted himself on the bed. "O-oh... Th-that's what you meant...!" He meekly squeaked out.

Frisk grinned evilly. "Oh, yes..." He opened the box, pulling out a condom and a bottle of strawberry scented lube. He also pulled out a tight looking spiked collar and leash.

Asriel panted apprehensively. "Haah... I-I guess... Yeah..."

Frisk climbed onto the bed and nuzzled his brother. "Hey, if you don't wanna do this..."

Asriel shook his head, quickly responding, "N-no, I _do_ want to...!" He smiled faintly. "I'm just a little... Drunk-y..."

Frisk giggled. "Silly, we both are..." He crawled up to face Asriel. He kissed his monster boyfriend, letting his tongue roam the inside of Asriel's mouth. By now, both boys were rock hard; Asriel started to grind on Frisk's knee, sending waves of pleasure through his body.

Frisk broke the kiss, smiling warmly, yet somewhat evilly. "Oh, no you don't... I get to have fun before you do." He lightly draped his hands around the monster boy's neck, pulling Asriel's head down to Frisk's stomach. With his head bent down, Frisk put the collar on Asriel and attached the leash, pulling it. Asriel yipped in surprise as Frisk's free hand suddenly forced his head towards the human boy's crotch, heavily implying what was to come next.

Asriel obediently opened his mouth and put all 16cm in his mouth, feeling Frisk's tip hit the back of his throat. He gagged slightly and pulled back a bit, but Frisk was enjoying himself too much. He thrust his hips forward, shoving his cock back down Asriel's throat.

Asriel started sucking his boyfriend off, enjoying the taste and feel of the moment. Frisk moaned and gasped frequently, the alcohol still strongly coursing through him, intensifying the pleasure.

"Mmn... Azzy... W-when did you learn to do this...?"

All Asriel could manage was a severely muffled, "Mmnf...!" and Frisk giggled, still panting and blushing madly. Frisk stopped Asriel's sucking by putting his hand on Asriel's head and pushing it back, allowing him to stand up as Asriel gasped for breath.

"F-Frisk, why'd you stop...? I was enjoying that..."

Frisk smirked. "Well then, it isn't punishment, now is it?" He grabbed the condom and lube from the nightstand beside their bed and sat down on the bed, legs crossed facing Asriel and the wall.

Asriel blushed a severely dark red. "H-haaah...! I... I'm so horny...! Please just do it... We don't need that..."

Frisk shook his head somewhat forcefully. "Yes, we do," he said, ending that conversation right there.

Asriel moaned with impatience as Frisk tore open the wrapper and pulled it out. "Go faster then...!"

Frisk looked at his lover, somewhat annoyed. "Here, you do it then." He handed Asriel the condom and grabbed the bottle of lube, squirting some into his hand. "Take it out and put it on me."

Asriel squeaked from sheer hornyness and obliged. While he was about to put the condom on Frisk, the human boy suddenly grabbed Asriel's ass and put two fingers at the opening to his hole. Asriel froze as Frisk slowly put them in, going up as far he could.

"F-Frisk...! I-I-" he moaned louder than ever before as Frisk scissored his fingers, stretching Asriel's hole wide. Asriel dropped the condom and grabbed Frisk, holding him close and scratching his back. Frisk winced but kept thrusting his fingers, nuzzling Asriel's warm chest as he did so.

This continued for several minutes until Frisk decided that Asriel was stretched enough. He took his fingers out carefully and grabbed the lube bottle again, this time putting some directly onto his dick. While Asriel instinctively bent over, head down and ass up, Frisk briefly jacked himself off to coat his cock with the lube.

Kneeling directly behind Asriel, Frisk murmured, "Ready?" He received a nod in response, and positioned himself over Asriel's now wide hole.

Forgetting the condom completely, Frisk put his rock-hard cock into Asriel's ready hole. He thrust in easily, going all the way up to his balls as the monster boy half-gasped, half-moaned for a solid ten seconds. Frisk stayed in this position for a few more seconds before beginning to thrust, growing in speed as they both grew more used to the feeling. By now both boys had lost all other senses of the world around them, feeling nothing but the animalistic urge inside as waves of pleasure coursed through their bodies. Frisk continued thrusting, harder and harder, while Asriel was lost, drowned out in wave after wave of pure ecstasy. They stayed like this, Frisk occasionally tugging at Asriel's collar and biting his neck, for almost half an hour. Asriel was now jacking himself off, but had to stop frequently before he came too close to finishing.

Finally, Frisk moaned loudly, "A-Azzy, I'm so close...!"

Asriel moaned and nodded, jacking off once more. "F-finish inside me...!"

Frisk gasped several time before crying out as he came, dumping his load into the monster boy. His eyes were shut tight in pure ecstasy, and all he could do was thrust and gasp. Asriel, feeling the warm cum hit the inside of his hole, gasped sharply and came only several seconds after that.

When Frisk finally stopped, he pulled out and collapsed next to Asriel, who slumped down onto his stomach. Frisk cuddled closer to his adopted brother, sighing in happiness.

As Asriel started to drift off, he heard a faint whisper of, "I love you," and smiled softly. He was truly happy.

 ** _*  
Later..._**

Toriel unlocked the front door of her house and entered. Seeing the bathroom light on, she walked to it and turned it off. Noticing the clothes still strewn about on the bathroom floor, she made a soft, "Tsk, tsk..." and picked them up, carrying them to the laundry room.

She made her way to the kitchen and opened the fridge. Finding nothing particularly enticing, she opened the freezer and looked for something to heat up.

She noticed a bottle, put back haphazardly, and moved it to it's correct location before realisation hit her.

 _"This... This bottle seems awfully empty..."_

 **Author's Note:** Cliffhangers are fun. Bye!


End file.
